Soluble oil



United States Patent M 2,993,857 SOLUBIJE OIL Louis H. Sudholz, Flushing, N.Y., assignor to Socony Mobil Oil Company, Inc., a corporation of New York No Drawing. Filed Apr. 10, 1958, Ser. No. 727,531 7 Claims. (Cl. 25232.7)

This invention relates to an improved lubricating composition and more particularly to a composition especially adapted for lubricating metals during processing operations such as cutting including broaching, turning, threading, drilling, tapping and milling and operations such as grinding, drawing, rolling and the like. By way of conventional designation in the art, the lubricating composition with which the present invention is concerned fall within the class commonly referred to as soluble oils. These as is well known, comprise a lubricating oil having dissolved or dispersed therein an emulsifying material imparting to the oil a capacity for substantial aqueous dilution to form a stable oil-in-water emulsion. f

The emulsion so formed is utilized by flowing over the tool and the work in a steady stream, and functions to dissipate the heat from both the tool and the work; improve tool life; improve the quality of the surface produced; lubricate the surfaces in contact between the tool and the work; wash away the chips; decrease tool wear; decrease friction between chip and tool; and provide lubrication between the chip and the tool, thus re. ducing the effect of the high pressure of the chip on the tool. Oil-in-water emulsions are normally usedwhere roughing cuts are being made. In roughing cuts, the primary object is to remove material and the quality of the surface produced has been. considered secondary. However, since in the subsequent finishing cut only a very small amount of material is removed, the preceding rough out should notleave the work in such a condition that the finishing cut will not remove the scars left by the rough cut. Therefore, the nature of the cutting oil used during the roughing out should be such as-toimprove the quality of the surface being worked.' There is ordinarily an enormous pressure exerted between the cutting edge of the tool and v the metalbeing machined and in addition, due to the inherent resiliency of the metal, heavy pressures. are maintained between the work and the-surface of thetool just-under the cutting'edge and between the chips arid-the surface of the tool just back of the cutting edge. Therefore, it is requisite that a lubricant be provided which is capable; of reducing friction and affordi ha high load-carryingtfilm of lubricantbetween the cutting tool, chip and the work beingmachined- Heretofore a variety of additives have been used in order to fortify soluble oils. Materials containing active sulfur are typical of such additives. While they areadvantageous in certain respects, high concentrations of active sulfur tend to cause corrosion and/or staining of certain metals when in contact therewith at relativelylow temperatures. I- Ialogen-contai ning additives, and PHI-l ticularly chlorinated materials, have also been used. However, the latteralso ,may;cause staining under humid conditions and often lose halogen, asphlgrine, during use.,, Phosphorusrontaining materials haveg been used butghere too, disadvantages. have been found. Many, phosphorus-containing additives, such as acid esters of phosphorus, combine with iron fines during use (particularly grinding operations) and form iron soaps may promote excessive foam formation. I g

It is-an object, therefore, of th present invention to provide an improved composition-adapted for lubrication during metal processing operations,- freeof the aforementioned disadvantages.

Patented July 25, 1961 Another object is to provide a metal processing lubricant characterized by a high degree of machining efliciency.

Other objects will be apparent from the following description.

The foregoing objects are realized with a soluble oil containing certain oil-soluble, phosphorus-, sulfurand metal-containing reaction products, which are the subject of application Serial No. 554,930, filed December 23, 1955, by Henry G. Berger et al., which issued as United States Patent No. 2,830,949 on April 15, 1958, and one or more suitable emulsifying agents. As described in said application, the reaction products are prepared by: l) forming a mixture of a hydrocarbon material, such as a petroleum oil, and a metal hydroxide; (2) contacting said mixture with an oxidizing gas at a temperature of from about C. to about 325 C. to provide a metalcontaining oxidized hydrocarbon product; (3) reacting the metal-containing oxidized hydrocarbon product with a phosphorus sulfide to provide a metal-, phosphorus and sulfur-containing oxidized hydrocarbon product; (4) forming a mixture of the product produced in (3) with water and a metal hydroxide at a temperature below the boiling point of water; (5) substantially completely dehydrating the mixture formed in (4); and (6) filtering the dehydrated mixture from (5) to remove insolubles therefrom. i

. Details for the character and preparation of these reaction products are given in the aforementioned patent application, and such details are incorporated herein by reference. However, a typical and preferred reaction product is given by way of illustration in Example '1 following. i

. EXAMPLE 1' Two thousand grams of a percolated, solvent refined Mid-Continent type bright stock (average molecular weight, about 800) and 200 grams (9.1 .weight percent) of hydrated lime (available calcium oxide, 70% minimum) were mixed and then charged to an electrically heated glass column (60 feet in length, 3 inches in diameter). Thecolumn has a fritted glass disc sealedin the bottom for air dispersion. The contents of the column were heated rapidly to 425" Air was introduced. through the glass frit at a rate'of 3 liters per hour per l00 grams ofoil for about 21 hours. The product thus formed was filtered. The filtrate has a calcium content frornabout 1.5-1.7 percent by weight. I

' The filtered oxidized oil is charged to a glass flask equipped with a stirrer, thermometer and a nitrogen inlet tube; The oil was diluted with an equal weight of, a dilution -oil; this is a parafiinic 'oil' having: an A.P.I. gravity of 27.5; and S.U.S. viscosity at 100 F. of 100-110; afiash (C.O.C., 'F.) of .350, minimum; and a color -(A.S.T.-M.)' of 2,maximum. About 10 percent by weight of P 8 based upon the bright stock charge,.isi added to-the diluted oxidized oil, and the resulting-mix-- ture was'reacted at 300 F. for 2 hours in an atmosphere of 'nitrogen. Following this, the reaction mixture was cooledto 180 F. and was treated with 10 percent by weight of water, and then with 10 percent by weight" of hydrated lime; the quantities-ofwat er and of li irie'are" based upon the bright stock charge. IThe mixture thus;

formed. was dehydrated when heated to a temperature.

andlthe product-was filtered hot through a"Hyflo coated,

' electricallypheated funnel- The filtrate, representing the 2,993,857 H a a desired reaction product in the dilution oil (1:1 dilution) has an analysis of the following character:

Calcium, percent 1.5-2.8 Phosphorus, percent 0.9-1.4 Sulfur, percent 1.5-3.0

A reaction product so prepared is shown in several tests hereinafter and is identified as Reaction Product A.

It has also been found that the dehydrated product can be used in the cutting oils of this invention, thus dispensing with the filtration step.

The concentration of reaction product in the soluble oil composition is such as to improve the machining efficiency thereof and may be varied widely in accordance with the use to which it is to be put. Where the emulsion is to be employed as a coolant, as well as a lubricant and applied by a circulating pump or the like, the reaction product should ordinarily be present in a concentration of from about 0.1% to about 3.0% by weight. Generally, a soluble oil will be marketed to be diluted for use as required. In such a soluble oil, the reaction prodnot will usually be present in a concentration of from about to about 30%. Thus, the compositions of the present invention contemplates the presence of the said reaction products in soluble cutting oils in widely varying amounts.

Although a wide range of mineral lubricating oils may be employed as the base for the soluble cutting oils described herein, in general the base oil comprises an oil having a Saybolt Universal viscosity at 100 F. in the range of from about 40 to about 1000 seconds, and an A.P.I. gravity of 19 to 36. However in preparing the present compositions, it is preferred to use a light oil as the base, that is, one having a gravity in the range of from 20 to'36 A.P.I. and a viscosity at 100 F. of from 80 to 120 seconds.

As indicated above, the compositions of this invention contain one or more emulsifying agents in combination with the above-mentioned reaction products and oils. Emulsifying agents useful herein include water-soluble soaps, sulfonates, cationic and non-ionic agents, all of which are well known in the art. 'lypical and illustrative of such materials are: sodium and potassium salts of animal and vegetable fats and fatty acids such as oleic, stearic and the like; mineral oil sulfonates prepared from a variety of mineral oil fractions; glyoxalidines such as l-hydroxyethyl-2-heptadecenyl glyoxalidine; hexahydric alcohol partial esters of high molecular weight fatty acids and the anhydrides thereof, such as sorbitan monooleate; polyoxyethylene derivatives of the above-mentioned hexa hydric alcohol partial esters; alkylated aryl poly-ether alcohols such as obtained by condensation of a phenol or phenol derivative with ethylene oxide, an illustration of which is a polyoxyethylene octylphenol. These emulsifying agents may be denominated as promoting the formation of oil-in-water emulsions, as shown in Patent No. 2,811,489, of Ernst Laug. They are present in the compositions of this invention in concentrations from about 5 percent to about 30 percent by weight, preferably from about to about percent.

The compositions of this invention accordingly comprise the combination of recited components in the following proportions:

In addition to the foregoing components, the soluble oils contemplated herein can also contain an extreme pressure agent of either corrosive or non-corrosive char acter, A corrosive. agent is characterized by ftlooselye 4 bound sulfur and is one which causes more than a slight discoloration in the copper strip test. This test involves immersion of a copper strip in the test material for three hours at 212 F. A non-corrosive agent is one which causes no more than a slight discoloration of a copper strip under such test conditions.

It is to be understood that in addition to having loosely-bound sulfur, the corrosive extreme pressure agents can contain one or more other characterizing elements such as bromine, chlorine, nitrogen, oxygen and phosphorus.

Representative of corrosive, sulfur-containing organic compositions in which sulfur is loosely-bound are the following: sulfurized animal, marine, and vegetable oils containing from about 12 to about 20 percent of sulfur; sulfurized mineral oils containing up to about 5 percent of added sulfur; sulfurized terpenes, organic polysulfides and mercaptans. Of such agents, particularly preferred is sulfurized lard oil containing about 15 percent by weight of sulfur.

Non-corrosive extreme pressure agents which can be used herein are characterized by firmly-bound sulfur, phosphorus, and/or halogen such as chlorine and bromine. Typical of such agents are: sulfurized animal, marine, and vegetable oils containing up to about 10 percent by weight of sulfur; dibenzyl disulfide; chlornaphtha xanthate; chlorinated fatty materals such as chlorinated stearic acids; chlorinated waxes; organic phosphorus compounds such as thiophosphates; etc. Preferred of such agents is sulfurized lard oil containing about 10 percent by weight of sulfur.

The corrosive and non-corrosive extreme pressure agents can be used in the compositions herein in concentrations from about 5 percent to about 20 percent, preferably between about 10 and 15 percent.

The compositions of this invention have proven to be advantageous in a number of respects, as is demonstrated by the following test data:

Tapping efficiency In the measurement of tapping efliciency of an oil, a series of holes is accurately drilled in a test metal, namely, SAE 1020 hot rolled steel. These holes are subsequently tapped with a series of taps in a drill press equipped with a table, which is free to rotate about the center, being mounted on ball bearings. A torque arm is attached to this floating table and this arm, in turn, actuates a spring scale so that the actual torque during tapping with the oil being evaluated is measured directly. The same taps used in evaluating the test oil are employed in tapping with a standard reference oil, which has arbitrarily been assigned an efliciency of 100 percent. The average torque for the test oil is compared to that of the standard and a relative efiiciency is calculated on a percentage basis. For example:

Torque with standard reference 011 19. 3 Torque with test nil 19. 8

Relative effielency of test oi1=%-':X100

Ta ping etfiel n Composition: pereen "Light duty soluble oil-1 part,

Water-15 parts 10%.reactlon product A light duty soluble oil ge e r g P rts d t A t I a reac 1011 pro 10 ght dutys'oluble bu} H w-1'11 "r:- r -,--.-,-.-.w--,-- 93 Water-15 partq l tapping test results reveal the machining efficiency ofj'tlie new compositions. Further, the results indicate that'a light duty soluble oil containing reaction product A, approaches heavy duty soluble oils in performance. The light duty soluble oil used is a mineral oil having a viscosity of 100 seconds (SUS at, 100 F.) compounded with emulsifiers so that the resultant product is readily emulsified with water. The light duty soluble oil contained (by weight): 13 percent of potassium soaps of rosin fatty acids; 7 percent of sodium mineral oil sulfonates (molecular weight of sulfonic acids, about 400); 1.5'percent of ethylene glycol, and 1 percent of Water.

Falex snap test One of the new soluble oils was subjected to the Falex snap test which is described in Bulletin No. 3, Faville LeVaHyCorpo'ration, Chicago, Illinois. This 'was comparedwith the lightdu'ty'soluble oil described above in connection with the tapping test. The test results are The Falex snap test evaluates the anti-weld characteristics, extreme pressure and lubricity properties of the oil under test. The higher the value obtained, the better the oil in these respects. As indicated by the foregoing test results, reaction product A provides substantial improvement to the light duty soluble oil. In fact, the value obtained with the oil containing the said reaction product is somewhat higher than the value obtained with a commercial, heavy duty sulfurized soluble oil.

It is to be understood that the above description is merely illustrative of preferred embodiments of the invention of which many variations can be made within the scope of the following claims by those skilled in the art without departing from the spirit thereof.

Iclaim:

1. A soluble oil composition consisting essentially of a mineral lubricating oil, from about percent to about 30 percent by weight of an emulsifying agent capable of promoting the formation of an oil-in-water emulsion, from about 5 percent to about 20 percent by weight of a corrosive sulfur-containing extreme pressure agent selected from the group consisting of sulfurized animal, marine and vegetable oils containing from about 12 to about 20 percent of sulfur, sulfurized mineral oils containing up to about 5 percent of added sulfur, sulfurized terpenes, organic polysulfides and mercaptans, and from about 5 percent to about 30 percent by weight of an oilsoluble, phosphorus-, sulfurand calcium-containing oxidized hydrocarbon reaction product produced by the method which comprises the steps of: (1) forming a mixture comprising (a) a hydrocarbon having a molecular weight of from about 200 to 1000 and which is selected from the group consisting of aliphatic hydrocarbons and aromatic hydrocarbons having at least one nuclear hydrogen atom substituted by an aliphatic radical to provide a total of at least 8 aliphatic carbon atoms per molecule therein, and mixtures thereof, and (b) from about 0.5% to about 25%, based on the weight of said hydrocarbon, of calcium hydroxide, (2) contacting said mixture with an oxidizing gas at a temperature of from about 125 C. to about 325 C. to eifect oxidation of said hydrocarbon and reaction of said calcium hydroxide with the oxidized hydrocarbon; (3) continuing the oxidation for a time sufiicient to incorporate from about 0.05% to about 3.0%, by weight, of calcium into the oxidized hydrocarbon; (4) reacting the product from (3) with from about 5% to about 20%, by weight, based on the weight of hydrocarbon charged in (1), of a phosphorus sulfide, at-a temperature of from about 75 C.

toabout 150 C., to form a phosphorus, sulfur- .and calcium-containing product; (5) providing a mixture of the reaction product from (4) with from about 2% to about 25% by weight, based on the hydrocarbon charged in (1), of a calcium hydroxide, and water, at a temperature below the boiling point of water; (6) substantially completely dehydrating the mixture formed in (5 and (7) subjecting the dehydrated mixture to filtra-' tion to remove insolubles therefrom.

2. A composition as defined by claim 1 wherein the corrosive extreme pressure agent is a sulfurized lard oil containing about 15 percent by weight of sulfur.

3. An oil-in-wateremulsion comprising one part by volume of the composition defined by claim 1 diluted with from about 10 to about 50 parts by volume of water.

4. A soluble oil composition consisting essentially of a mineral lubricating oil, fromabout 5 to about 30 percent by weight of an emulsifying agent capable of promoting the formation of an oil-in-water emulsion, from about 5 percent to about 20 percent by weight of a noncorrosive sulfur-containing extreme pressure agent selected from the group consisting of sulfurized animal, marine and vegetable oils containing from about 12 to about 20 percent of sulfur, sulfurized mineral oils containing up to about 5 percent of added sulfur, sulfurized terpenes, organic polysulfides and mercaptans, and from about'S percent to about 30 percent by weight of an oil-soluble, phosphorus-, sulfurand calcium-containing oxidized hydrocarbon reaction product produced by the method which comprises the steps of: (1) forming a mixture comprising (a) a hydrocarbon having a molecular weight of from about 200 to 1000 and which is selected from the group consisting of aliphatic hydrocarbons and aromatic hydrocarbons having at least one nuclear hydrogen atom substituted by an aliphatic radical to provide a total of at least 8 aliphatic carbon atoms per molecule therein, and mixtures thereof, and (b) from about 0.5% to about 25%, based on the weight of said hydrocarbon, of a calcium hydroxide, (2) contacting said mixture with an oxidizing gas at a temperature of from about C. to about 325 C. to effect oxidation of said hydrocarbon and reaction of said calcium hydroxide with the oxidized hydrocarbon; (3) continuing the oxidation for a time sufiicient to incorporate from about 0.05% to about 3.0%, by weight, of calcium into the oxidized hydrocarbon; (4) reacting the product from (3) with from about 5% to about 20%, by weight, based on the weight of hydrocarbon charged in (1), of a phosphorus sulfide, at a temperature of from about 75 C. to about C., to form a phosphorus-, sulfurand calcium-containing product; (5 providing a mixture of the reaction product from (4) with from about 2% to about 25%, by weight, based on the hydrocarbon charged in (1), of a calcium hydroxide, and water, at a temperature below the boiling point of water; (6) substantially completely dehydrating the mixture formed in (5 and (7) subjecting the dehydrated mixture to filtration to remove insolubles therefrom.

5. A composition as defined by claim 3 wherein the non-corrosive extreme pressure agent is a sulfurized lard oil containing about 10 percent by weight of sulfur.

6. An oil-in-Water emulsion comprising one part by volume of the composition defined by claim 3 diluted with from about 10 to about 50 parts by volume of water.

7. A soluble oil composition consisting essentially of a mineral lubricating oil, from about 5 percent to about 30 percent by weight of an emulsifying agent capable of promoting the formation of an oil-in-Water emulsion, and from about 5 percent to about 30 percent by weight of an oil-soluble, phosphorus-, sulfurand calcium-containing oxidized hydrocarbon reaction product produced by the method which comprises the steps of: (1) forming -7 a mixture comprising (a) a hydrocarbon having a molecular weight of from about 200 to 1000 and which is selected from the group consisting of aliphatic hydrocarbons and aromatic hydrocarbons having at least one nuclear hydrogen atom substituted by an aliphatic radical to provide a total of at least 8 aliphatic carbon atoms per molecule therein, and mixtures thereof, and (b) from about 0.5% to about 25%, based on the weight of said hydrocarbon, of a calcium hydroxide, (2) contacting said mixture with an oxidizing gas at a temperature of from about 125 C. to about 325 C. to effect oxidation of said hydrocarbon and reaction of said calcium hydroxide with the oxidized hydrocarbon; (3) continuing the oxidation for a time suflicient to incorporate from about 0.05% to about 3.0%, by weight, of calcium into the oxidized hydrocarbon; (4) reacting the product from (3) with from about to about 20%, by weight, based on the weight of hydrocarbon charged in (1), of a phosphorus 8 sulfide, at a temperature of from about C. to abwt Q, to form a phosphorus-, sulfurandcaiciumcontaining product; (5 providing a mixtureo! thereaction product from (4) with from about 2% to about 25%, by weight, based on the hydrocarbon charged in (1), of a calcium hydroxide, and water, at a temperature below the boiling point of water; and (6) substantially completely dehydrating the mixture formed in (5).

References Cited in the file of this patent UNITED STATES PATENTS I 2,375,315 Mixon May 8, 1945 2,631,129 Waugh Mar. 10, 1953 2,773,861 Musselman Dec. 11, 1956 2,830,949 Berger et a1 Apr. 15, 1958 2,846,393 Cook et a1. Aug. 5, 1958 2,864,846 Gragson Dec. 16, 1958 UNITED :STATES' PATENT. OFFICE CERTIFICATE OF CORRECTION Patent No. 2 -993,a57 July 25, I961 Louis H. Sudholz 7 It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

for "composition" read compositions for "'floating" read "Floating" ference numeral Column 1 line 15 column i line 47,

column 6 lines 62 and 66; for the claim re "3"" each occurrence read 4 Signed and sealed this 27th day of February 1962.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer DAVID L. LADD Commissioner of Patents 

1. A SOLUBLE OIL COMPOSITION CONSISTING ESSENTIALLY OF A MINERAL LUBRICATING OIL, FROM ABOUT 5 PERCENT TO ABOUT 30 PERCENT BY WEIGHT OF AN EMULSIFYING AGENT CAPABLE OF PROMOTING THE FORMATION OF AN OIL-IN-WATER EMULSION, FROM ABOUT 5 PERCENT TO ABOUT 20 PERCENT BY WEIGHT OF A CORROSIVE SULFUR-CONTAINING EXTREME PRESSURE AGENT SELECTED FROM THE GROUP CONSISTING OF SULFURIZED ANIMAL, MARINE AND VEGETABLE OILS CONTAINING FROM ABOUT 12 TO ABOUT 20 PERCENT OF SULFUR, SULFURIZED MINERAL OILS CONTAINING UP TO ABOUT 5 PERCENT OF ADDED SULFUR, SULFURIZED TERPENES, ORGANIC POLYSULFIDES AND MERCAPTANS, AND FROM ABOUT 5 PERCENT TO ABOUT 30 PERCENT BY WEIGHT OF AN OILSOLUBLE, PHOSPHORUS-, SULFUR- AND CALCIUM-CONTAINING OXIDIZED HYDROCARBON REACTION PRODUCT PRODUCED BY THE METHOD WHICH COMPRISES THE STEPS OF: (1) FORMING A MIXTURE COMPRISING (A) A HYDROCARBON HAVING A MOLECULAR WEIGHT OF FROM ABOUT 200 TO 1000 AND WHICH IS SELECTED FROM THE GROUP CONSISTING OF ALIPHATIC HYDROCARBONS AND AROMATIC HYDROCARBONS HAVING AT LEAST ONE NUCLEAR HYDROGEN ATOM SUBSTITUTED BY AN ALIPHATIC RADICAL TO PROVIDE A TOTAL OF AT LEAST 8 ALIPHATIC CARBON ATOMS PER MOLECULE THEREIN, AND MIXTURES THEREOF, AND (B) FROM ABOUT 0.5% TO ABOUT 25%, BASED ON THE WEIGHT OF SAID HYDROCARBON, OF CALCIUM HYDROXIDE, (2) CONTACTING SAID MIXTURE WITH AN OXIDIZING GAS AT A TEMPERATURE OF FROM ABOUT 125*C. TO ABOUT 325*C. TO EFFECT OXIDATION OF SAID HYDROCARBON AND REACTION OF SAID CALCIUM HYDROXIDE WITH THE OXIDIZED HYDROCARBON; (3) CONTINUING THE OXIDATION FOR A TIME SUFFICIENT TO INCORPORATE FROM ABOUT 0.05% TO ABOUT 3.0%, BY WEIGHT, OF CALCIUM INTO THE OXIDIZED HYDROCARBON; (4) REACTING THE PRODUCT FROM (3) WITH FROM ABOUT 5% TO ABOUT 20%, BY WEIGHT, BASED ON THE WEIGHT OF HYDROCARBON CHARGED IN (1), OF A PHOSPHORUS SULFIDE, AT A TEMPERATURE OF FROM ABOUT 75*C. TO ABOUT 150*C., TO FORM A PHOSPHORUS-, SULFUR- AND CALCIUM-CONTAINING PRODUCT; (5) PROVIDING A MIXTURE OF THE REACTION PRODUCT FROM (4) WITH FROM ABOUT 2% TO ABOUT 25%, BY WEIGHT, BASED ON THE HYDROCARBON CHARGED IN (1), OF A CALCIUM HYDROXIDE, AND WATER, AT A TEMPERATURE BELOW THE BOILING POINT OF WATER; (6) SUBSTANTIALLY COMPLETELY DEHYDRATING THE MIXTURE FORMED IN (5) AND (7) SUBJECTING THE DEHYDRATED MIXTURE TO FILTRATION TO REMOVE INSOLUBLES THEREFROM. 